Solve for x: x² - 10x + 21 = 0
Difficulty: Medium
About this MCQ
Medium GMAT item. Correct choice: A. x = 3 or x = 7.
- A. x = 3 or x = 7 ✓
- B. x = 4 or x = 6
Why not B: “x = 4 or x = 6” is not x = 3 or x = 7.
- C. x = 3 or x = 8
Why not C: “x = 3 or x = 8” is not x = 3 or x = 7.
- D. x = -3 or x = -7
Why not D: “x = -3 or x = -7” is not x = 3 or x = 7.
Correct answer
A. x = 3 or x = 7
Explanation
x = 3 or x = 7 (option A) is the accepted answer to “Solve for x: x² - 10x + 21 = 0”. Option B (x = 4 or x = 6) is a different value from x = 3 or x = 7. Option C (x = 3 or x = 8) is a different value from x = 3 or x = 7. Option D (x = -3 or x = -7) is a different value from x = 3 or x = 7. Keep x = 3 or x = 7 as the GMAT fact for this stem.
Source: Original practice question, MCQsHub
Tags: Math, Algebra, American Exams, GMAT
Submitted by: MCQsHub Editorial
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